Fix mount directory for containerized-build-release-binaries script
Fix mount directory for containerized-build-release-binaries script

The containerized-build-release-binaries script file needs to be updated to reflect the new mount directory. (This is a consequence of the move kubernetes-incubator).

 Otherwise the script fails:

```
main.go:6:2: cannot find package "github.com/kubernetes-incubator/kube-aws/cmd" in any of:
        /go/src/github.com/coreos/kube-aws/vendor/github.com/kubernetes-incubator/kube-aws/cmd (vendor tree)
        /usr/local/go/src/github.com/kubernetes-incubator/kube-aws/cmd (from $GOROOT)
        /go/src/github.com/kubernetes-incubator/kube-aws/cmd (from $GOPATH)
```

everpeace/kube-aws,everpeace/kube-aws,kubernetes-incubator/kube-aws,HotelsDotCom/kube-aws,HotelsDotCom/kube-aws,mumoshu/kube-aws,danielfm/kube-aws,c-knowles/kube-aws,iflix-letsplay/kube-aws,mumoshu/kube-aws,camilb/kube-aws,danielfm/kube-aws,c-knowles/kube-aws,kubernetes-incubator/kube-aws,iflix-letsplay/kube-aws,camilb/kube-aws